The Bowline

To tie the knot move the mouse along the numbers 1 - 10.
Alternate between 10 and Structure to see the structure.

Uses: The Bowline (ABOK # 1010, p 186) makes a reasonably secure loop in the end of a piece of rope. It has many uses, e.g., to fasten a mooring line to a ring or a post. Under load, it does not slip or bind. With no load it can be untied easily. It's principle shortcoming is that it cannot be tied, or untied, when there is a load on the standing end. It should therefore be avoided when, for example, a mooring line may have to be released under load. Two bowlines can be linked together to join two ropes.

One Handed: The bowline can be tied with one hand - useful if injured, essential if you are using the other hand to hold on to the line or the boat!

Can Untie If Not Loaded: A bowline makes a poor safety knot for a swimmer. When a bowline is unloaded, it can very readily work its way untied - I know, it has happened to me! Fortunately I only lost a scrubbing brush.

Alternative Structures: When tied as shown in the illustrations above, the bitter end lies in the middle of the loop. Passing the end the opposite way round the standing end forms a "Dutch Marine" or "Left Handed" bowline (see right). It performs satisfactorily - the Dutch Navy says better - but is much less used in other countries.

Safety: An intermittent load, e.g., on a mooring line, may cause many knots to slip or loosen. The bowline is relatively tolerant of such stresses. Nevertheless some texts quote a rule of thumb which states that the loose end should be as long as 12 times the circumference for the sake of safety. The principle is sound but, for a half inch diameter rope, this would indicate a tail more than eighteen inches long and this is rarely seen in practice.

Another recommendation is that when used for man-carrying applications a figure of eight knot should be tied in the loose (bitter) end, or, perhaps most secure of all, the free end should be fastened to the adjoining loop with a double overhand knot (picture on left) - see Climbing Section